Internal Relays M And F, Latch Relay L; Special Relay For Link (Sb), Special Register For Link (Sw); Link Relay B, Link Register W - Mitsubishi Electric M800VW Series Programming Manual

M800V/M80V Series PLC Programming Manual (1/2)
4 Explanation of Devices
4.4 Detailed Explanation of Devices

4.4.2 Internal Relays M and F, Latch Relay L

The internal relay and latch relay are auxiliary relays in the PLC that cannot directly output to an external source.
Internal relay M
 It will be cleared when the power is turned OFF.
 There is no limit to the number of "A" contacts and "B" contacts of the internal relays that can be used in the program.
 The internal relay No. is expressed with a decimal.
Internal relay F
Internal relay F is an interface for the alarm message display.
Use the bit selection parameter to determine whether to use this relay for the alarm message interface. The target will be
all F0 to F1023. This internal relay can be used in the same manner as the internal relay M when not used as the alarm
message interface.
Latch relay L
 The original state is held even when the power is turned OFF.
 There is no limit to the number of "A" contacts and "B" contacts of the latch relay that can be used in the program.
 The latch No. is expressed with a decimal.

4.4.3 Special Relay for Link (SB), Special Register for Link (SW)

Special relay for link (SB)
 This interacts between various kinds of network cards and PLC programs.
 ON/OFF control is applied due to various factors occurred at the time of data link. By monitoring the special relay for
link, abnormal state of data link can be detected.
Special register for link (SW)
 This interacts between various kinds of network cards and PLC programs.
 Information at the time of data link is stored. By monitoring the special register for link, abnormal area and the cause
can be examined.

4.4.4 Link Relay B, Link Register W

 Link relay B is the bit type device that performs data link with various link functions.
Unused area can be used as the temporary memory, etc.
 Link register W is the word type device that performs data link with various link functions.
Unused area can be used as the temporary memory, etc.
Link Relay B, Link Register W
 It will be cleared when the power is turned OFF.
 There is no limit in the number that can be used in the program.
 The relay and register No. are expressed with a hexadecimal.
35 IB-1501667-B